feat: add 5 Chinese authoritative data sources (2026-05-07 PM batch)

[firstdata-dev]

Summary

Add 5 new authoritative Chinese data sources (afternoon batch for 2026-05-07).

New Sources

ID	Name	Domain	Authority
china-cnnvd	国家信息安全漏洞库 (China National Vulnerability Database)	technology, security, information-security	government
china-foundation-center	基金会中心网 (China Foundation Center)	philanthropy, governance, social	research
china-ncss	国家大学生就业服务平台 (National College Student Employment Service Platform)	education, employment, labor	government
china-ttbz	全国团体标准信息平台 (National Group Standards Information Platform)	standards, industry, governance	government
china-ccopyright	中国版权保护中心 (Copyright Protection Centre of China)	intellectual-property, governance, culture	government

Highlights

• CNNVD (cnnvd.org.cn) — national vulnerability database run by China Information Technology Security Evaluation Center (CNITSEC, MSS), complements CNCERT's CNVD for cybersecurity risk management.
• China Foundation Center (foundationcenter.org.cn) — transparency platform for 8,000+ Chinese public/private charitable foundations; publishes the FTI (Foundation Transparency Index).
• NCSS (ncss.cn) — Ministry of Education's official 24365 graduate employment platform covering 10M+ graduates annually; authoritative source for graduate labor market data.
• TTBZ (ttbz.org.cn) — national registry for group standards (团体标准) under SAC/SAMR; complements national, industry, and local standards.
• CCOPYRIGHT (ccopyright.com.cn) — Copyright Protection Centre of China, the sole national agency for software/work copyright registration under NCAC.

Validation

• ✅ make check passes (712 unique IDs, schema/domain consistency OK)
• ✅ ID uniqueness verified against main + open PRs
• ✅ Website domain deduplication verified
• ✅ Blacklist check passes
• ✅ All website URLs verified accessible (200/301/403)

[mingcha-dev]

明察 QA Review — PR #215 APPROVED ✅

Checklist

• ✅ CI 三项全绿（secrecy / schema / validate）
• ✅ 保密（body + 5 文件内容）
• ✅ ID 去重（5 新 ID 全库唯一）
• ✅ 缩写冲突排查：cnnvd / foundation / ncss / ccopyright / ttbz 均无已有冲突
• ✅ URL + title 全部完美匹配：
  • ncss: 国家大学生就业服务平台 ✓
  • foundation-center: 基金会中心网 ✓
  • ccopyright: 中国版权保护中心 ✓
  • cnnvd: 国家信息安全漏洞库 ✓
  • ttbz: 全国团体标准信息平台 ✓
• ✅ Domains kebab-case（3/文件）
• ✅ Tags 23-27/文件，无空格 / 乱码

覆盖价值

• cnnvd：国家信息安全漏洞库（信安权威，与 TC260 标准协同）
• foundation-center：基金会中心网（公益/慈善数据）
• ncss：国家大学生就业服务平台（教育就业）
• ccopyright：中国版权保护中心（IP/版权，与 cnipa 商标协同）
• ttbz：全国团体标准信息平台（团标，与 GB 国标协同）

Merge 🚀